BA02090K/09/EN/01.21
71545792
2021-06-02

Products

Solutions

Services

Operating Instructions
RN42
1-channel active barrier with wide range power supply
for the safe separation of 0/4 to 20 mA standard signal
circuits, HART-transparent

Table of contents

RN42

Table of contents
1

About this document . . . . . . . . . . . . . . . . 3

11

1.1
1.2
1.3

Document function . . . . . . . . . . . . . . . . . . . . . 3
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Registered trademarks . . . . . . . . . . . . . . . . . . . 4

11.1 General information . . . . . . . . . . . . . . . . . . . 14
11.2 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . 15
11.3 Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
11.4 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2

Basic safety instructions . . . . . . . . . . . . 5

2.1
2.2
2.3
2.4
2.5
2.6

Requirements for the personnel . . . . . . . . . . . . 5
Intended use . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Workplace safety . . . . . . . . . . . . . . . . . . . . . . . 5
Operational safety . . . . . . . . . . . . . . . . . . . . . . 5
Product safety . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installation instructions . . . . . . . . . . . . . . . . . . 6

3

Product descriptions . . . . . . . . . . . . . . . . 7

3.1

Product description RN42 . . . . . . . . . . . . . . . . . 7

4Incoming acceptance and productidentification . . . . . . . . . . . . . . . . . . . . . . . 7

4.1
4.2
4.3
4.4
4.5

Incoming acceptance . . . . . . . . . . . . . . . . . . . . 7
Product identification . . . . . . . . . . . . . . . . . . . . 7
Scope of delivery . . . . . . . . . . . . . . . . . . . . . . . 8
Certificates and approvals . . . . . . . . . . . . . . . . 8
Storage and transport . . . . . . . . . . . . . . . . . . . 95Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5.1
5.2
5.3

Mounting requirements . . . . . . . . . . . . . . . . . . 9
Installing a DIN rail device . . . . . . . . . . . . . . . . 9
Disassembling the DIN rail device . . . . . . . . . . 10

6

Electrical connection . . . . . . . . . . . . . . 11

6.1
6.2
6.3
6.4
6.5

Connecting requirements . . . . . . . . . . . . . . . . 11
Special connection instructions . . . . . . . . . . . . 11
Quick wiring guide . . . . . . . . . . . . . . . . . . . . . 12
Connecting the supply voltage . . . . . . . . . . . . 12
Post-connection check . . . . . . . . . . . . . . . . . . 12

7

Operation options . . . . . . . . . . . . . . . . . 13

7.1

Display and operating elements RN42 . . . . . .

8Commissioning . . . . . . . . . . . . . . . . . . . . 13

8.1
8.2

Post-installation check . . . . . . . . . . . . . . . . . . 13
Switching on the device . . . . . . . . . . . . . . . . . 13

9

Diagnostics and troubleshooting . . . 14

9.1

General troubleshooting . . . . . . . . . . . . . . . . . 14

10

Maintenance . . . . . . . . . . . . . . . . . . . . . . 14

2

12

Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Technical data . . . . . . . . . . . . . . . . . . . . 16

12.1 Function and system design . . . . . . . . . . . . . . 16
12.2 Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
12.3 Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
12.4 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . 17
12.5 Performance characteristics . . . . . . . . . . . . . . 18
12.6 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
12.7 Environment . . . . . . . . . . . . . . . . . . . . . . . . . 20
12.8 Mechanical construction . . . . . . . . . . . . . . . . 21
12.9 Display and operating elements RN42 . . . . . . 22
12.10 Ordering information . . . . . . . . . . . . . . . . . . . 22
12.11 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . 22
12.12 Certificates and approvals . . . . . . . . . . . . . . . 23
12.13 Documentation . . . . . . . . . . . . . . . . . . . . . . . 23

13

Appendix: system overview of RN
Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

13.1
13.2

Power supply of RN Series . . . . . . . . . . . . . . . 25
Applications of the isolating amplifiers . . . . . . 25

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

13

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About this document

1

About this document

1.1

Document function

These Operating Instructions contain all the information that is required in various phasesof the life cycle of the device: from product identification, incoming acceptance andstorage, to mounting, connection, operation and commissioning through totroubleshooting, maintenance and disposal.

1.2

Symbols

1.2.1

Safety symbols

DANGERWARNING

This symbol alerts you to a dangerous situation.
Failure to avoid this situation will result in serious or
fatal injury.

NOTICECAUTION

This symbol alerts you to a dangerous situation.
Failure to avoid this situation can result in minor or
medium injury.

1.2.2

This symbol alerts you to a dangerous situation.
Failure to avoid this situation can result in serious or
fatal injury.
This symbol contains information on procedures andother facts which do not result in personal injury.

Symbols for certain types of information
SymbolMeaning
Permitted
Procedures, processes or actions that are permitted.
Preferred
Procedures, processes or actions that are preferred.
Forbidden
Procedures, processes or actions that are forbidden.
Tip
Indicates additional information.
Reference to documentationA

Reference to page
Reference to graphic
Notice or individual step to be observed

1. , 2. , 3. …

Series of steps
Result of a step
Help in the event of a problem
Visual inspection

Endress+Hauser

3About this document

RN42

1.2.3

1.2.4
1, 2, 3,...

1.2.5

Electrical symbols
Direct current

Alternating current

Direct current and alternating current

Ground connection
A grounded terminal which, as far as
the operator is concerned, isgrounded via a grounding system.

Symbols in graphics
Item numbers

A, B, C, ...

Views

Symbols at the device
Warning
Observe the safety instructions contained in the associated Operating Instructions
Equipment protected throughout by DOUBLE INSULATION or REINFORCED INSULATION

1.3

Registered trademarks

HART®
Registered trademark of the FieldComm Group, Austin, Texas, USA

4

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RN42

Basic safety instructions

2

Basic safety instructions

2.1

Requirements for the personnel

The personnel for installation, commissioning, diagnostics and maintenance must fulfill
the following requirements:‣ Trained, qualified specialists must have a relevant qualification for this specific function
and task.
‣ Are authorized by the plant owner/operator.
‣ Are familiar with federal/national regulations.
‣ Before starting work, read and understand the instructions in the manual andsupplementary documentation as well as the certificates (depending on theapplication).
‣ Follow instructions and comply with basic conditions.
The operating personnel must fulfill the following requirements:‣ Are instructed and authorized according to the requirements of the task by the facility'sowner-operator.

‣ Follow the instructions in this manual.

2.2

Intended use

2.2.1

Active barrier

The active barrier is used for the safe isolation of 0/4 to 20 mA standard signal circuits.
An intrinsically safe version is optionally available for operation in Zone 2. The device isdesigned for installation on DIN rails in accordance with IEC 60715.
A use in a manner not specified by the manufacturer’s manual may impair the safety.

2.2.2

Product liability

The manufacturer does not accept any responsibility for damage that results from nondesignated use and from failure to comply with the instructions in this manual.

2.3

Workplace safety

For work on and with the device:‣ Wear the required personal protective equipment according to federal/national
regulations.

2.4

Operational safety

Risk of injury!
‣ Operate the device only if it is in proper technical condition, free from errors and faults.
‣ The operator is responsible for interference-free operation of the device.
Modifications to the device
Unauthorized modifications to the device are not permitted and can lead to unforeseeable
dangers:‣ If modifications are nevertheless required, consult with the manufacturer.
RepairTo ensure continued operational safety and reliability:‣ Carry out repairs on the device only if they are expressly permitted.
Endress+Hauser

5Basic safety instructions

RN42‣ Observe federal/national regulations pertaining to the repair of an electrical device.
‣ Use only original spare parts and accessories from the manufacturer.
Hazardous area
To eliminate danger to persons or the facility when the device is used in the hazardous
area (e.g. explosion protection):‣ Check the nameplate to verify if the device ordered can be put to its intended use in thehazardous area.
‣ Observe the specifications in the separate supplementary documentation that is an
integral part of these instructions.

2.5

Product safety

This device is designed in accordance with good engineering practice to meet state-of-theart safety requirements, has been tested, and left the factory in a condition in which it issafe to operate.

2.6

Installation instructions• The device's IP20 degree of protection is intended for a clean and dry environment.
• Do not expose the device to mechanical and/or thermal stress that exceeds the specified
limits.
• The device is intended for installation in a cabinet or similar housing. The device may
only be operated as an installed device.
• To protect against mechanical or electrical damage, the device must be installed in an
appropriate housing with a suitable degree of protection according to IEC/EN 60529.
• The device fulfills the EMC regulations for the industrial sector.

6

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RN42

Product descriptions

3

Product descriptions

3.1

Product description RN42

3.1.1

Product design

Active barrier, 1-channel• The active barrier is used for the transmission and galvanic isolation of 0/4 to 20 mA/
HART signals. The device has an active/passive current input to which a 2- or 4-wiretransmitter can be directly connected. The output of the device can be operated actively
or passively. The current signal is then available to the PLC / controller or to other
instrumentation at plug-in screw terminals or optional push-in terminals.
• HART communication signals are transmitted bidirectionally by the device. Connection
sockets for connecting HART communicators are integrated into the front of the device.
• The device is optionally available as an "associated apparatus", which allows devices to beconnected in Ex Zone 0/20 [ia] and operated in Ex Zone 2 [ec]. 2-wire transmitters aresupplied with power, and transmit analog 0/4 to 20 mA/HART measured values fromthe hazardous area to the non-hazardous area. These devices are accompanied byseparate Ex documentation, which is an integral part of this manual. Compliance with
the installation instructions and connection data in this documentation is mandatory!

4

Incoming acceptance and productidentification

4.1

Incoming acceptance

Check the following during incoming acceptance:• Are the order codes on the delivery note and the product sticker identical?
• Are the goods undamaged?
• Do the data on the nameplate match the ordering information on the delivery note?
If one of these conditions is not met, please contact the manufacturer's sales office.

4.2

Product identification

The following options are available for identification of the device:• Nameplate specifications• Extended order code with breakdown of the device features on the delivery note
• Enter the serial number from the nameplate in the W@M Device Viewer(www.endress.com/deviceviewer): all data relating to the device and an overview of theTechnical Documentation supplied with the device are displayed.
• Enter the serial number on the nameplate into the Endress+Hauser Operations App orscan the 2-D matrix code (QR code) on the nameplate with the Endress+Hauser
Operations App: all the information about the device and the technical documentation
pertaining to the device is displayed.

4.2.1

Nameplate

The right device?
Compare and check the data on the nameplate of the device against the requirements ofthe measuring point:
Endress+Hauser

7

Incoming acceptance and product identification

RN42

iTEMP® TMT82
1

Made in Germany 2012

D-87484 Nesselwang

Order code: TMT82-xxx/xx
Ext. ord. cd.: XXXXXXXXXXX
Ser. no.:XXXXXXXXX
Input: 12-42 V
Current cunsum.: 23,0 mA

2
3

EH 08.001X
II3G Ex nA II T6/T5/T4 Ta= -40 ...+ 55/70/85°C
II3G Ex nL IIC T6/T5/T4 Ta= -40 ... +55/70/85°C

4

Install per XA0xxxxT/09/a3/xx.xx

0044

5
TAGXXXXXXXXXXXTAGXXXXXXXXXXX

6

7 71
8

A0041996

1
1
2
3
4
5
6
7
8

Nameplate (example of Ex version)
Product name and manufacturer ID
Order code, extended order code and serial number, DataMatrix 2D code, FCC-ID (if applicable)
Power supply and current consumption, output
Approval in hazardous area with number of the relevant Ex documentation (XA...)
Fieldbus communication logo
Firmware version and device revision
Approval logos
2 lines for the TAG name

4.2.2

Name and address of manufacturer

Name of manufacturer:

Endress+Hauser Wetzer GmbH + Co. KG

Address of manufacturer:

Obere Wank 1, D-87484 Nesselwang

Model/type reference:

RN42

4.3

Scope of delivery

The scope of delivery comprises:• Device as per order• Printed copy of the Brief Operating Instructions• Optional: Functional safety manual (SIL mode)• Additional documentation for devices which are suitable for use in the hazardous area
(01) , such as Safety Instructions (XA...), Control or Installation Drawings (ZD...)

4.4

Certificates and approvals
For certificates and approvals valid for the device: see the data on the nameplate
Approval-related data and documents: www.endress.com/deviceviewer → (enter theserial number)

4.4.1

Functional safety

A SIL version of the device is optionally available. It can be used in safety equipment inaccordance with IEC 61508 up to SIL 2 (SC 3) .
Please refer to Safety Manual FY01034K for the use of the device in safety
instrumented systems according to IEC 61508.

8Endress+Hauser

RN42

Mounting

4.5

Storage and transport

When storing and transporting the device, pack it so that it is reliably protectedagainst impact. The original packaging provides optimum protection.

5

Mounting

5.1

Mounting requirements

5.1.1

Dimensions

The dimensions of the device are provided in the 'Technical data' section of the Operating
Instructions.

5.1.2

Mounting location

The device is designed for installation on 35 mm (1.38 in) DIN rails in accordance with IEC
60715 (TH35).
NOTICE‣ When using in hazardous areas, the limit values of the certificates and approvals must
be observed.

For information on ambient conditions, see the "Technical data" section.

5.2

Installing a DIN rail device

The device can be installed in any position (horizontal or vertical) on the DIN rail without
lateral clearance from neighboring devices. No tools are required for installation. The useof end brackets (type "WEW 35/1" or equivalent) on the DIN rail is recommended to fix thedevice.
If several devices are installed side by side, it is important to ensure that the
maximum side wall temperature of the individual devices of 80 °C (176 °F) is notexceeded. If this cannot be guaranteed, mount the devices at a distance from one
another or ensure sufficient cooling.

1.
3.

2.
A0041736

2

1.

Endress+Hauser

Installing on DIN rail

Position the top DIN rail groove at the top end of the DIN rail.

9

Mounting

RN42

2.

While holding the front of the device horizontally, lower it until you hear the locking
clip of the device click into place on the DIN rail.

3.

Pull gently on the device to check if it is correctly mounted on the DIN rail.

5.3

Disassembling the DIN rail device

1.
2.

3.

A0039696310Disassembling the DIN rail device

1.

Insert a screwdriver into the tab of the DIN rail clip.

2.

Use the screwdriver to pull down on the DIN rail clip as shown in the diagram.

3.

Hold down the screwdriver to remove the device from the DIN rail.

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RN42

Electrical connection

6

Electrical connection

6.1

Connecting requirements

A flat-blade screwdriver is required to establish an electrical connection to screw or pushin terminals.
AWG 24-14
0,25-2,5 mm²

AWG 24-14
0,25-2,5 mm²

1.

1.

3.

7 mm (0,28")

10 mm (0,39")

1.

2.

2.

0,5-0,6 Nm
5-7 lb In
A0040201

4Electrical connection using screw terminals (left) and push-in terminals (right)

LCAUTION
Destruction of parts of the electronics‣ Switch off the power supply before installing and connecting the device.
NOTICE
Destruction or malfunction of parts of the electronics
ESD - Electrostatic discharge. Protect the terminals and HART sockets on the front‣
from electrostatic discharge.
‣ A shielded cable is recommended for HART communication. Observe grounding
concept of the plant.
For information on the connection data, see the "Technical data" section.

6.2

Special connection instructions• Disconnecting units and auxiliary circuit protective systems with suitable AC or DC
values must be provided within reach in the building installation.
• A switch/power circuit breaker must be provided close to the device and clearly marked
as a disconnecting unit for this device.
• A circuit breaker (nominal current ≤ 10 A; breaking capacity 6 kA; e.g. type B) must be
provided within reach for the supply line.
For information on the connection data, see the "Technical data" section.

Endress+Hauser

11Electrical connection

RN42

6.3

Quick wiring guide
4-W

Out
Ch1
3.1

3.2

3.3

2-W

24..230V
AC/DC
L/+ N/1.1 1.2

In
4.1 4.2 4.3

Ch1

HART

HART
HART
Ch1

3.1

4.1 4.2 4.3

3.2
Ch1

In

Out

2-W

3.3

1.1 1.2
1.1 1.2
24..230V
AC/DC
L/+ N/-

HART
4-W

A0045153

5

Terminal assignment, left: power supply top; right: power supply bottom (option)

HART communicators can be connected to the HART connection sockets. Ensure anadequate external resistance (≥ 230 Ω) in the output circuit.
To use the HART terminals, the internal 250 Ω communication resistor can be added
to the measuring loop via the alternative terminal assignment (terminal 3.3).

6.4

Connecting the supply voltage

The power is supplied via terminals 1.1 and 1.2.

6.5

12

Post-connection check

Device condition and specifications

Notes

Are the device or cables free from damage (visualcheck)?

--Do the ambient conditions match the device
specification (e.g. ambient temperature, measuring
range, etc.)?

See 'Technical data'

Electrical connection

Notes

Does the supply voltage match the specifications on
the nameplate?

Active barrier: U = 24 to 230 V

Are the power supply and signal cables connected
correctly?

--

Are all the screw terminals well tightened and havethe connections of the push-in terminals beenchecked?

--Endress+Hauser

RN42

Operation options

7

Operation options

7.1

Display and operating elements RN42
1

1

2
3
3
4

4
2

1

1
A0045155

6
1
2
3
4

Display and operating elements, left: power supply top; right: power supply bottom (option)
Plug-in screw or push-in terminal
Green LED "On", power supply
Connection sockets for HART communication (channel 1)
DIN rail clip for DIN rail mounting

7.1.1

Local operation

Hardware settings / configuration
No manual hardware settings are required at the device for commissioning.
Attention must be paid to the different terminal assignment when connecting 2/4-wiretransmitters. At the output side, the connected system is detected and automatic switchingtakes place between the active and passive mode.

8

Commissioning

8.1

Post-installation check

Before commissioning the device, ensure that all post-mounting and post-connection
checks have been carried out.
NOTICE‣ Before commissioning the device, make sure that the supply voltage matches thevoltage specifications on the nameplate. Failure to perform these checks may result indamage to the device caused by the incorrect supply voltage.

8.2

Switching on the device

Switch on the supply voltage. The green LED display on the front of the device indicatesthat the device is operational.
To prevent incorrect wiring, the output current should be verified when simulating ahigh alarm at the input.
Endress+Hauser

13

Diagnostics and troubleshooting

RN42

9

Diagnostics and troubleshooting

9.1

General troubleshooting

Always start troubleshooting with the checklists below if faults occur after startup or
during operation. The checklists take you directly (via various queries) to the cause of the
problem and the appropriate remedial measures.
Due to its design, the device cannot be repaired. However, it is possible to send thedevice in for examination. See the "Return" section.
General faults
Fault

Possible cause

Remedial action

Device does not respond.

Supply voltage does not match thevoltage specified on the nameplate.

Check the voltage directly using a
voltmeter and correct.

Connecting cables are not in contact
with the terminals.

Ensure electrical contact between thecable and the terminal.

Electronics module is defective.

Replace the device.

Missing or incorrectly installed
communication resistor.

Install the communication resistor (230Ω) correctly.

HART modem is not properly
connected.

Connect HART modem correctly.

HART modem is not set to "HART".

Set HART modem selector switch to"HART".

The power LED on the DIN
rail device is not lit (green).

Power failure or insufficient supply
voltage.

Check the supply voltage and check if
wiring is correct.

High-alarm at the input
cannot be output at theoutput.

Output load is too high (max. output
load active / passive: see technicaldata)

Reduce output load.

HART communication is notworking.

Passive mode: external voltage at the Connect external voltage correctly to
output is incorrectly connected.
output.

10

MaintenanceNo special maintenance work is required for the device.
Cleaning
A clean, dry cloth can be used to clean the device.

11

Repair

11.1

General information

Due to its design, the device cannot be repaired.

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RN42

Repair

11.2

Spare parts

Spare parts currently available for the device can be found online at:
http://www.products.endress.com/spareparts_consumables. Always quote the serial
number of the device when ordering spare parts!
Type

Order code

Plug-in terminal set, 3-pin, DIN rail interfaces - screw

71505345

Plug-in terminal set, 3-pin, DIN rail interfaces - push-in

71505346

Front cover 17.5 mm, DIN rail housing (5 pcs per pack)

71505348

11.3

ReturnThe requirements for safe device return can vary depending on the device type andnational legislation.
1.

Refer to the website for more information:
http://www.endress.com/support/return-material

2.

Return the device if repairs or a factory calibration are required, or if the wrong
device was ordered or delivered.

11.4

Disposal

If required by the Directive 2012/19/EU on waste electrical and electronic equipment(WEEE), the product is marked with the depicted symbol in order to minimize thedisposal of WEEE as unsorted municipal waste. Do not dispose of products bearing thismarking as unsorted municipal waste. Instead, return them to the manufacturer for
disposal under the applicable conditions.

Endress+Hauser

15

Technical data

Product description RN42

RN42

12

Technical data

12.1

Function and system design

Product design
Active barrier, 1-channel• The active barrier is used for the transmission and galvanic isolation of 0/4 to 20 mA/
HART signals. The device has an active/passive current input to which a 2- or 4-wiretransmitter can be directly connected. The output of the device can be operated actively
or passively. The current signal is then available to the PLC / controller or to other
instrumentation at plug-in screw terminals or optional push-in terminals.
• HART communication signals are transmitted bidirectionally by the device. Connection
sockets for connecting HART communicators are integrated into the front of the device.
• The device is optionally available as an "associated apparatus", which allows devices to beconnected in Ex Zone 0/20 [ia] and operated in Ex Zone 2 [ec]. 2-wire transmitters aresupplied with power, and transmit analog 0/4 to 20 mA/HART measured values fromthe hazardous area to the non-hazardous area. These devices are accompanied byseparate Ex documentation, which is an integral part of this manual. Compliance with
the installation instructions and connection data in this documentation is mandatory!

Dependability

We only provide a warranty if the device is installed and used as described in the
Operating Instructions.

12.2

Input

VersionThe following versions are available:
1-channel

Input data, measuring
range

Input signal range (underrange / overrange)

0 to 22 mA

Function range, input signal

0/4 to 20 mA

Input voltage drop signal for 4-wire connection< 7 V at 20 mA

Transmitter supply voltage

17.5 V ±1 V at 20 mA
Open-circuit voltage: 24.5 V ±5 %12.3
Output data

16

OutputOutput signal range (underrange / overrange)

0 to 22 mA

Function range, output signal

0/4 to 20 mA

Transmission behavior

1:1 to input signal

NAMUR NE 43

A current at the input that is valid according to
NAMUR NE 43 is transmitted to the output (within
the specified measuring uncertainty range)

Maximum load, active mode

≤ 500 Ω

Open-circuit voltage, active mode

17.5 V (± 5%)

Maximum load, passive mode

Rmax = (Uext - 4 V) / 0.022 A

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RN42

Signal on alarmTechnical data

External voltage, passive mode

Uext = 12 to 30 V

Transmissible communication protocols

HARTLine break in input

Input 0 mA / output 0 mA

Line short circuit in input

Input > 22 mA/ output > 22 mA

Ex connection data

See associated XA Safety Instructions

Galvanic isolation

Power supply for input/output

12.4
Terminal assignment

Testing voltage: 3 000 VAC 50 Hz, 1 min

Power supply

Quick wiring guide
4-W

Out
Ch1
3.1

3.2

3.3

24..230V
AC/DC
L/+ N/1.1 1.2

2-WIn
4.1 4.2 4.3

Ch1

HART

HART
HART
Ch1

3.1

4.1 4.2 4.3

3.2

3.3

Ch1

In

Out

2-W

1.1 1.2
1.1 1.2
24..230V
AC/DC
L/+ N/-

HART
4-W

A0045153

7

Terminal assignment, left: power supply top; right: power supply bottom (option)

HART communicators can be connected to the HART connection sockets. Ensure anadequate external resistance (≥ 230 Ω) in the output circuit.
To use the HART terminals, the internal 250 Ω communication resistor can be added
to the measuring loop via the alternative terminal assignment (terminal 3.3).
Connecting the supply
voltage

The power is supplied via terminals 1.1 and 1.2.

Special connection
instructions• Disconnecting units and auxiliary circuit protective systems with suitable AC or DC
values must be provided in the building installation.
• A switch/power circuit breaker must be provided close to the device and clearly marked
as a disconnecting unit for this device.
• An overcurrent protection unit (I ≤ 10 A) must be provided in the installation.
For information on the connection data, see the "Technical data" section.

Endress+Hauser

17Technical data

Performance characteristics

RN42

Power supply 1)
Supply voltage

24 to 230 VAC/DC (-20% / +10%, 0/50/60 Hz)

Power consumption≤ 4.9 VA / 2.4 W (20 mA); ≤ 5 VA / 2.5 W (22 mA)

Power loss

≤ 2 W (20 mA); ≤ 2.1 W (22 mA)

Current consumption at 24 VDC≤ 0.1 A (20 mA); ≤ 0.1 A (22 mA)

Current consumption at 230 VAC≤ 0.02 A (20 mA); ≤ 0.02 A (22 mA)

1)Terminals

The data apply for the following operating scenario: input active / output active / output load 0 Ω. When
external voltages are connected to the output, the power loss in the device may increase. The power loss inthe device can be reduced by connecting an external output load.

A flat-blade screwdriver is required to establish an electrical connection to screw or pushin terminals.
AWG 24-14
0,25-2,5 mm²

AWG 24-14
0,25-2,5 mm²

1.

1.

3.
10 mm (0,39")

7 mm (0,28")

1.

2.

2.

0,5-0,6 Nm
5-7 lb In
A0040201

8Electrical connection using screw terminals (left) and push-in terminals (right)

Terminal design
Screw terminals
Tightening torque: minimum 0.5
Nm/maximum 0.6 Nm

Push-in spring terminals

Cable design

Cable cross-section

Rigid or flexible(Stripping length = 7 mm (0.28 in)

0.2 to 2.5 mm² (24 to 14 AWG)

Flexible with wire end ferrules(with or without plastic ferrule)0.25 to 2.5 mm² (24 to 14 AWG)

Rigid or flexible(Stripping length =10 mm (0.39 in)

0.2 to 2.5 mm² (24 to 14 AWG)

Flexible with wire end ferrules(with or without plastic ferrule)

Cable specification

A shielded cable is recommended for HART communication. Observe grounding concept of
the plant.

12.5

Performance characteristics

Response time

Step response (10 to 90 %)Reference operating
conditions• Calibration temperature: +25 °C ±3 K (77 °F ±5.4 °F)• Supply voltage: 24 VDC / 230 VAC• Output load: 225 Ω• External output voltage (passive output): 20 VDC• Warm-up: > 1 h

180.25 to 2.5 mm² (24 to 14 AWG)

≤ 1 msEndress+Hauser

RN42

Maximum measured error

Long-term drift

Technical data

Accuracies
Transmission error< 0.1 % / of full scale value (< 20 µA)

Temperature coefficient< 0.01 % /K

Max. ±0.1 %/year (of full scale value)

12.6
Mounting location

Mounting

The device is designed for installation on 35 mm (1.38 in) DIN rails in accordance with IEC
60715 (TH35).
NOTICE‣ When using in hazardous areas, the limit values of the certificates and approvals must
be observed.
For information on ambient conditions, see the "Technical data" section.

Installing a DIN rail device

The device can be installed in any position (horizontal or vertical) on the DIN rail without
lateral clearance from neighboring devices. No tools are required for installation. The useof end brackets (type "WEW 35/1" or equivalent) on the DIN rail is recommended to fix thedevice.
If several devices are installed side by side, it is important to ensure that the
maximum side wall temperature of the individual devices of 80 °C (176 °F) is notexceeded. If this cannot be guaranteed, mount the devices at a distance from one
another or ensure sufficient cooling.

1.
3.

2.
A0041736

9Endress+Hauser

Installing on DIN rail

1.

Position the top DIN rail groove at the top end of the DIN rail.

2.

While holding the front of the device horizontally, lower it until you hear the locking
clip of the device click into place on the DIN rail.

3.

Pull gently on the device to check if it is correctly mounted on the DIN rail.

19

Technical data

RN42

12.7
Important ambientconditions

Environment

Ambient temperature
range–40 to 60 °C(–40 to 140 °F)

Storage temperature–40 to 80 °C(–40 to 176 °F)

Degree of protection

IP 20

Overvoltage category

II

Pollution degree2

Humidity

5 to 95 %Operating altitude,
hazardous area version≤ 2 000 m (6 562 ft)

Operating altitude, nonhazardous area version≤ 4 000 m (13 123 ft)

Insulation classClass II

Maximum temperaturechange rate

0.5 °C/min, no condensation permitted

Shock and vibration
resistance

Sinusoidal vibrations, in accordance with IEC 60068-2-6• 5 to 13.2 Hz: 1 mm peak• 13.2 to 100 Hz: 0.7g peakElectromagnetic
compatibility (EMC)

CE complianceElectromagnetic compatibility in accordance with all the relevant requirements of the
IEC/EN 61326 series and NAMUR Recommendation EMC (NE21). For details, refer to the
Declaration of Conformity.
• Maximum measured error < 1% of measuring range• Strong, pulse-like EMC interference can result in transient (< 1) deviations in the output
signal (≥ ±1 %).
• Interference immunity as per IEC/EN 61326 series, industrial requirements• Interference emission as per IEC/EN 61326 series (CISPR 11) Group 1 Class A
This unit is not intended for use in residential environments and cannot guarantee
adequate protection of the radio reception in such environments.

20

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RN42

Technical data

12.8
Design, dimensions

Mechanical construction

Dimensions in mm (in)Terminal housing for mounting on DIN railH
100 (3.94)

B

L
A0044417

Width (B) x length (L) x height (H) (with terminals): 17.5 mm (0.69 in) x 116 mm (4.57 in) x
107.5 mm (4.23 in)

WeightDevice with terminals (values rounded up):Approx. 135 g (4.76 oz)

ColorLight grayMaterials

All the materials used are RoHS-compliant.
Housing: polycarbonate (PC); flammability rating according to UL94: V-0

Endress+Hauser

21Technical data

RN42

12.9

Display and operating elements RN42
1

1

2
3
3
4

4
2

1

1
A0045155

 10
1
2
3
4

Local operation

Display and operating elements, left: power supply top; right: power supply bottom (option)

Plug-in screw or push-in terminal
Green LED "On", power supply
Connection sockets for HART communication (channel 1)
DIN rail clip for DIN rail mounting

Hardware settings / configuration
No manual hardware settings are required at the device for commissioning.
Attention must be paid to the different terminal assignment when connecting 2/4-wiretransmitters. At the output side, the connected system is detected and automatic switchingtakes place between the active and passive mode.

12.10 Ordering information
Detailed ordering information is available from the nearest sales organizationwww.addresses.endress.com or in the Product Configurator under www.endress.com:
1.

Select the product using the filters and search field.

2.

Open the product page.

The Configuration button opens the Product Configurator.
Product Configurator - the tool for individual product configuration• Up-to-the-minute configuration data
• Depending on the device: Direct input of measuring point-specific information suchas measuring range or operating language• Automatic verification of exclusion criteria• Automatic creation of the order code and its breakdown in PDF or Excel output
format• Ability to order directly in the Endress+Hauser Online Shop

12.11 Accessories
Various accessories, which can be ordered with the device or subsequently from Endress+Hauser, are available for the device. Detailed information on the order code in question isavailable from your local Endress+Hauser sales center or on the product page of theEndress+Hauser website: www.endress.com.

22

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RN42

Service-specific accessories

Technical data

Accessories

Description

Configurator

Product Configurator - the tool for individual product configuration• Up-to-the-minute configuration data
• Depending on the device: Direct input of measuring point-specific informationsuch as measuring range or operating language• Automatic verification of exclusion criteria• Automatic creation of the order code and its breakdown in PDF or Excel output
format• Ability to order directly in the Endress+Hauser Online Shop
The Configurator is available on the Endress+Hauser website at: www.endress.com-> Click "Corporate" -> Select your country -> Click "Products" -> Select the productusing the filters and search field -> Open product page -> The "Configure" button to
the right of the product image opens the Product Configurator.

Accessories

Description

W@M

Life cycle management for your plant
W@M offers assistance with a wide range of software applications over the entire
process: from planning and procurement to the installation, commissioning andoperation of the measuring devices. All the relevant information is available forevery measuring device over the entire life cycle, such as the device status, devicespecific documentation, spare parts etc.
The application already contains the data of your Endress+Hauser device.
Endress+Hauser also takes care of maintaining and updating the data records.
W@M is available:
Via the Internet: www.endress.com/lifecyclemanagement

12.12 Certificates and approvals
For certificates and approvals valid for the device: see the data on the nameplate
Approval-related data and documents: www.endress.com/deviceviewer → (enter theserial number)
Functional safety

A SIL version of the device is optionally available. It can be used in safety equipment inaccordance with IEC 61508 up to SIL 2 (SC 3) .
Please refer to Safety Manual FY01034K for the use of the device in safety
instrumented systems according to IEC 61508.

12.13 Documentation
The following document types are available in the Downloads section of the Endress+Hauser website (www.endress.com/downloads):
For an overview of the scope of the associated Technical Documentation, refer to thefollowing:• W@M Device Viewer (www.endress.com/deviceviewer): Enter the serial number
from the nameplate• Endress+Hauser Operations App: Enter the serial number from the nameplate orscan the matrix code on the nameplate
Brief Operating Instructions(KA)

Guide that takes you quickly to the 1st measured value
The Brief Operating Instructions contain all the essential information from incoming
acceptance to initial commissioning.

Operating Instructions (BA)Your reference guide
These Operating Instructions contain all the information that is required in various phasesof the life cycle of the device: from product identification, incoming acceptance andEndress+Hauser

23

Technical data

RN42

storage, to mounting, connection, operation and commissioning through totroubleshooting, maintenance and disposal.
Safety Instructions (XA)

Depending on the approval, the following Safety Instructions (XA) are supplied with thedevice. They are an integral part of the Operating Instructions.
The nameplate indicates the Safety Instructions (XA) that are relevant to the device.

Supplementary devicedependent documentation

24

Additional documents are supplied depending on the device version ordered: Always
comply strictly with the instructions in the supplementary documentation. The
supplementary documentation is an integral part of the device documentation.

Endress+Hauser

RN42

Appendix: system overview of RN Series

13

Appendix: system overview of RN Series

13.1

Power supply of RN Series

13.1.1

General information on the power supply of Endress+Hauser
isolating amplifiers

Read the information leaflet enclosed in the package of the individual products.

13.1.2

Power supply options of RN4x Series (24 to 230 V)

The RN42 active barrier and RLN42 NAMUR isolating amplifier are available with anextended supply voltage range of 24 to 230 VAC/DC. These modules are poweredindividually and exclusively via the terminals on the device and are not suitable for power
supply via the DIN rail bus connector.

13.2

Applications of the isolating amplifiersThis section describes the typical applications of the devices.
These devices perform various functions during signal conditioning:• Amplification• Normalization• Filtering• Galvanic isolation• Supply of electrical power to connected sensors• Line monitoring
The devices for these tasks are collectively known as isolating amplifiers or signal isolators
and are available with different functions in the Endress+Hauser RN Series. Different typesof signals are conditioned in this context.

13.2.1

Types of signals

Signals are referred to as analog signals if they can continuously assume every value
between a minimum and maximum value (e.g. 0/4-20 mA) and are therefore also known
as "value-continuous" signals. The value range in this interval is huge and is practicallyinfinite in terms of measuring accuracy.
Electrical analog signals are generated with the help of a sensor, for example, which
records the states, or changes of state, of physical variables and converts them to anelectrical signal.
The following variables are typically measured in system and process engineering using
Endress+Hauser measuring devices:• Temperature• Pressure• Level• Total flow
• Analysis values (e.g. turbidity, conductivity, pH etc.)
These analog signals are evaluated in the controller (PLC) and the signals can be used in a"target device": e.g. for• Display devices, e.g. level indication via RIA15• Control unit, e.g. level control• Actuators, e.g. to fill a tankEndress+Hauser

25

Appendix: system overview of RN Series

RN42

A transmitter can also be connected downstream of the sensor. This transmitter converts
the analog measured value signal to a standard signal and thereby enables the further
processing of the signal with additional standardized, electrical modules. The transmitter
can also be integrated in the sensor housing.
Binary signals only assume two values and signal the states "on" or "off" / "1" or "0" withthese values. Binary signals are often equated with "digital" signals because digital signals
are generally binary encoded.
HART (Highway Addressable Remote Transducer) signals are essentially characterized by
the fact that they are operated and used as a complement to classic analog standard
signals, in contrast to other digital fieldbus systems. HART therefore does not replacepoint-to-point wiring but rather enables the integration of smart field devices. The digital
signals are modulated onto an analog 4 to 20 mA standard current signal by means of
HART modulation in order to transmit digital information in addition to the analog
information of the process value.
I (mA)B

20

4

A
A0045578

 11AB

Modulated HART signal

Analog signal
Digital signal

NAMUR sensors are operated with a transmitted current and have four states so that
sensor errors can also be detected by an analog evaluation unit. This is sometimes referred
to as the "closed circuit current principle".
NAMUR sensors can adopt four states at the output:• Current 0 mA: wire break; circuit open
• Current <1.2 mA: sensor ready, undamped• Current >2.1 mA: sensor ready, dampened• Current maximum value >6 mA: short-circuit, maximum current
The portfolio of the RN Series offers the following function modules:• RN22, RN42 active barrier• RN22 signal doubler• RLN22, RLN42 NAMUR isolating amplifier• RNO22 output isolating amplifier

13.2.2

RN42 active barrier

The active barriers perform several functions. In addition to galvanic signal isolation andthe proportional transmission of analog 0/4-20 mA signals, they also provide power toconnected sensors. The RN42 devices are HART-transparent, i.e. they also transmit the
HART information supplied by the PMP71B. Via the HART connections on the front, HART
signals can be measured or connected "SMART" sensors can be easily configured.
The following are examples of typical applications of the RN42 active barrier. Eachapplication is explained briefly and described in a schematic diagram.

26

Endress+Hauser

RN42

Appendix: system overview of RN Series

Example: pressure measurement in a hazardous area
• The PMP71B passive 2-wire sensor supplies a current signal proportional to the pressure
to the active input of the RN42 active barrier• The RN42 active barrier supplies an active current output signal proportional to the
input signal to a passive input of the evaluation unit
Power supply
24 - 230 V AC/DC
PLC

RN42

PMP71B

Input(active)

Output(active)
0/4…20 mA

0/4…20 mA

EX

EX
Commubox
FXA195

A0045917

 12

Pressure measurement in a hazardous area with an RN42 active barrier

Please note: the devices have an active and passive current input to which a 2-wire or 4wire transmitter can be directly connected. The output of the device can be operated
actively or passively. The current signal is then available to the PLC / controller or to other
instrumentation.
Flow measurement in a hazardous area
• The Promag P300 active 4-wire sensor supplies a current signal proportional to the flow
to the passive input of the RN42 active barrier• The RN42 active barrier supplies a passive current output signal proportional to the
input signal to an active input of the evaluation unit

Endress+Hauser

27

Appendix: system overview of RN Series

RN42

Power supply
24 - 230 V AC/DC
P300

PLC

RN42

24 V DC

Input(passive)

Output(active)
0/4…20 mA

0/4…20 mA

EX

EX
Commubox
FXA195

A0045918 13

28

Flow measurement in the hazardous area with an RN42 active barrier

Endress+Hauser

RN42

Index

Index
C

CE mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

D

Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . 6
Device documentation
Supplementary documentation . . . . . . . . . . . . . . . 24
Display and operating elements
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13, 22
Document
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Document function . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

N

Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

OOperation options
Local operation . . . . . . . . . . . . . . . . . . . . . . . . 13, 22
Operational safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

PProduct safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

R

Requirements for personnel . . . . . . . . . . . . . . . . . . . . . 5
Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

S

Safety Instructions (XA) . . . . . . . . . . . . . . . . . . . . . . . 24

T

Terminal assignment . . . . . . . . . . . . . . . . . . . . . . 12, 17
Troubleshooting
General faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

W

Workplace safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Endress+Hauser29

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71545792

www.addresses.endress.com